Roller-gearing.



Nu. 532,599. 'Patented sept. 5, |899.

c. L. TRAVIS.

ROLLER GEARING.

(Application filed Apr. 19, 1899,. (No Model.) 2 Sheets-Sheet I.

@Hoz/149134,.

No. 632,599. Patented Sept. 5, |899.

l c. L. TnAvls.

ROLLER GEARING.

(Appncation fnea Apr. 19, w99.)

2 Sheets-Sheet 2,

ma Model.)

N mils vrrzps co., PNOTMITMO.. WASHINGTON, D. c,

UNrTnD STATES' PATENT OFFICE.

OIIARLES L. TRAVIS, OF MINNEAPOLIS, MINNESOTA.

ROLLER-Gemme.

SPECIFICATION forming part of Letters Patent No. 632,599, datedSeptember 5, 1899'.

Application filed April 19, 1899. Serial No. 713,582. (No model.)

To f//ZZ whom, it bury concern:

Be it known that 1, CHARLES L. TRAvIs, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in Roller-Gearing, of which the following is a specification.

Myinvention pertains to gearing, and particularly to such as employsantifriction-rollers to constitute the engaging or intermesh ing membersor to take the place of the ordinary rigid teeth.

The invention may be embodied in bevelgearing, in spur-gearing, or inracks and pinions, as occasion requires, and the following descriptionand claims are to be read with this understanding, spur-gearingincluding both internal and external gears.

As the more immediate purpose of the present invention is to permit theemployment of rollers in lieu of rigid teeth in both of two intermeshingbevel gears or pinions, l have illustrated this construction in thedrawings; but I have also shown the invention as applied to a spur-wheeland rack, and I have also shown the roller-Wheel actin gin conjunctionwith a rigid-toothed rack and with a rigid-toothed wheel.

In the drawings, Figure l is a face elevation of a bevel gear or pinionembodying my invention; Fig. 2, a sectional view showing two such wheelsin operative relation or engagement; Fig. 3, an enlarged View showingthe construction and mode of mounting the rollers, portions being brokenaway to better show the arrangement and construction of parts g Fig. 4.,a sectional view illustrating the invention as applied to a spurwheeland rack; Fig. 5, a similar view showing the rack with rigid teethinstead of rollers; Fig. 6, a sectional view similar to Fig. 2, butshowing one of the bevel-wheels with rigid teeth.

Prior to my invention gearing has been made with rigid teeth, and insome cases with rollers to take the place of such rigid teeth; but inthe latter case the rollers have been applied usually to but one of twocoacting wheels or to the rack alone or the pinion alone, in the case ofa rack and pinion. Latterly attempts have been made to apply rollers totwo coacting wheels rotating in intersecting planes, this beingaccomplished by mounting the rollers upon axes parallel in each wheelwith the axis of such wheel and giving to the rollers a curved form inthe direction of their length. Other forms of roller-teeth have alsobeen proposed. My invention aims to maintain the general form of thewheels or wheel and rack, yet to apply to each the rollers and to causethe rollers of one to bear against and to coact with those of the othermember. Important points in the construction of gearing of this classare'the attainment and maintenance of perfect contact between therollers of respective teeth throughout their length or in the directionof their axes of rotation, provision for ready and accurate adjustmentof the rollers in the event of their being thrown in any degree out oftrue position in assembling or after the parts are assembled,

prevention of any disturbance in the proper relative adjustment of therollers in the act of securing them in place, and the avoidance of anynecessity for great accuracy in the drilling of the rivet-holes andbushings. So, too, it is highly important that the construction be suchthat the pressure on one end or section of the roller-tooth becounterbalanced by that on the other end or section, so that if, for anyreason, there be the slightest tendency of the rollers to bear unequallyat one end this counterbalancing effect shall bring them into trueline-bearing from end to end.

Referring now to the drawings and first to Figs. l, 2, and 3 thereof, Aindicates the body or disk and hub portion of a wheel, having aperipheral flange a, which is of a scalloped' form or is provided withalternate projections or ears b and depressions or recesses c, thelatter advisably of greater width than the intervening projections orears. The flange a will, in the lcase of spur-wheels or wheels designedto coact with another wheel or rack moving in the same or parallelplane, be in the same plane with the disk or body portion on which it isformed. In other words, the scalloped edge or alternate' projections anddepressions may be simply the outer edge or periphery of the disk in thevcase of spurgearing, but for bevel gears vor` wheels designed to impartmotion to another member moving in an intersecting plane the flange awill be set at an appropriate angle to the body or disk A, as shown inFigs. 2 and 3. The

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-or the ear b thereof.

angle at which the flange stands relatively to the body or disk portionwill of course vary according to the relative diameters of the twocoacting wheels. In Fig. 2 two such wheels are shown of equal diameterand their flanges a are accordingly set at an angle of forty-fivedegrees relatively to the body or disk portions.

The ears or projections b are designed to carry the supporting-axles ofa series of rollers, which rollers will in the case of spurgearing andracks be of cylindrical form, but in the case of bevel-gearing will beconical or tapering, the taper being such that straight lines contactingwith their surfaces and running in the general direction of their axeswill all meet in the point of intersect-ion of the axes of twocooperating wheels. B B indicate the rollers, which are made each in twosections, one on each side of the flange a The axles of the rollers Bare formed by short tubes or bushings C, similarly made in two sectionsand placed on opposite sides ofthe supporting or carrying ears b. Tofirmly secure these bushings or bearing-sleeves in their properpositions and to guard against any shifting or movement thereof, eitherlaterally or longitudinally, the ears are drilled or bored to receive afastening device, rivet, or bolt D, and both faces of said ears arecounterbored concentrically with the bolt or rivet hole to receive theinner ends of the sleeves or bushings C, as best shown in Fig. 3, thoughalso seen in Figs. 2 and 6. of a length sufficient to enter counterboredseats or'sockets d and to project from the faces of the ears orprojections b a distance slightly greater than the axial measurement ofthe rollers B. The sleeves or bushings being placed in position and therollers B being mounted thereon, the several parts4 are firmly andaccurately secured and retained in place by means'of a rivet D or itsequivalent, a bolt or like fastening, which is passed through thesleeves and the intervening ear b and properly secured in place. Inpractice it is found convenient and expedient to employ rivets,preferably of steel, having at one end a reasonably large andwell-formed head e and of such length as to permit the application of awasher f to its protruding end and to leave metal sufficient for theformation above or outside of said Washer of a'second head g. Therollers and the sleeves or bushings are by preference made of hardenedor tempered steel, while the rivet is made of mild steel or other metalor an alloy capable of being properly headed down, as explained. By theconstruction just described the sleeves f are held very rmly in placeand are absolutely precluded from shifting or tipping in any direction.A IIence if once properly set they will accurately locate and maintainin position the rollers B. y

It will be observed by reference to the several figures that the rollersB project beyond the edges or periphery of their supporting or Thesleeves or bushings C are madeA carrying ears I), and it will also benoted that the spaces c between said ears are of greater width than arethe ears themselves, measured in the planes of the axes of the rollers.The purpose of this relatively greater width of space is to precludecontact of the ears or rollers of one wheel with the ears of the otherwheel or in the case of a rack and pinion to prevent contact with theears of the rack or the pinion.

As above explained and as is indicated in Fig.l 2, the rollers B B areof tapering form, and the taper is such that lines drawn from the pointof intersection of the axes of the two coacting wheels will lie parallelor in contact with the surfaces of the rollers in the direction of theirlength. The rollers of the two wheels will therefore come together inthe same relation and act upon each other in the same way substantiallyas do the rigid teeth of ordinary bevel-gears, except that by reason oftheir ability to turn about their axes the rollers will substituterolling for sliding friction, and thus greatly reduce the frictionalresistance to rotation of the wheels.

By the construction j ust explained I am enabled to employ roller-teethor coacting rollers in lieu of teeth in two bevel-wheels or wheelsarranged to rotate in intersecting planes; but it is essential to thisresult that spaces, such as the depressions or spaces c, be left betweenthe ears or supports by which the rollers are carried, as otherwise theange d of one wheel would preclude its intermeshing with the otherwheel.

Y In Fig. 4 I have represented the ears or projections b as extendingoutward in the same plane with the body or disk A, the rollers and theirbushings and fastenings being shown in section, as otherwise thebushings would be hidden by the heads of the fastenings. It will be seenupon reference to this ligure that except for the inclination or angulararrangement of the flange or the scalloped periphery of the wheel it isthe same in this as in the preceding figures, and so, too, of the rack Ewith which said Wheel is shown coacting.

Fig. 5 is the same as Fig. 4, except that the rack E is represented ashaving rigid teeth instead of rollers. The teeth in such case should berather longer and more slen der than are the teeth of racks designed foruse with ordinary toothed gears. v

Fig. 6 represents the roller bevel-pinion co'- acting with arigid-toothedbevel-pinion, the teeth being spaced somewhat wider andmade longer and more slender than the teeth of ordinary. bevel-gears toadapt them the better to cooperate with the roller gear or pinion.

It will be observed that under the several embodiments of the inventionhere represented all tendency of the axles to twist, cant, o r tip inany direction is counteracted, first, by the seating of the ends of thesleeves in the the counterbored faces of the supporting or carrying earsand the clamping of them in such position by the rivets or fastenings D,

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and, second, by the equal pressure applied to the rollers on oppositesides of each ear or carrying projection b.

The construction above set forth is simple, light, and cheap, andaffords great facilities for vdrilling and assembling the parts and foradjusting them inthe event that any ear be thrown slightly out ofposition or any hole be bored in the least degree out of properinclination.

The hub may be tapped or threaded or otherwise adapted to be secu red upon an axleshaft or other member.

In the manufacture of wheels of this class the drilling of therivet-holes and the boring of the counter-seats for the sleeves orbushings may be done by one and the same tool to advantage. The properlocation and spacing of the counter-seats for the bushings require greataccuracy, to the end that the sleeves or bushings when seated thereinshall be at the precise distance from one another and from the axis ofthe wheel necessary to close-fitting of the gear-teeth or rollers and toprevent lost motion or backlash. The bushings being thus accuratelylocated and being held by the solid surrounding metal cannot bedisplaced laterally. If, therefore, the hole through the bushing or therivet-hole in line with the interior opening of the bushing be notaccurately located with reference to the circumference of thecounterseat in which the bushing is placed, such inaccuracy is whollyimmaterial and may be completely disregarded. So, too, the bushingsbeing produced by automatic machines and gaged to absolute uniformity oflength, the rollers being similarly produced and the counter-seats boredby stop mechanism to precise and uniform depth, it follows that therivets may be headed down wit-hout great care, but with the certaintythat the bushings will be secured with the utmost accuracy in theirproper positions and without danger or liability of causing therivet-heads or the washers thereunder to bind or bear upon the rollers.The bushings being of tempered metal and of relatively broad base orlarge diameter cannot be rocked or tipped in their seats in a manner tobind or cramp the rollers, as might be done in the case of a simplerivet or throughpin soft enough to be headed or riveted down.

Owing to the fact that there is a roller on each side of the web orflange and that the pressure is brought upon both sides simultaneously,if by any possibility one of the ears should be thrown very slightly outof its true position the strain thus brought upon the rollers would tendto spring or twist the ear back to its proper position, the play ormovement being, however, exceedingly slight in any case. If in thecourse of manufacture, during or after assembling of the parts by reasonof dropping the gear or through an inaccurate stroke of theriveting-hammer or any like cause, an ear be bent or thrown out ofposition, it may readily be brought back to its true position by placingit in the jig or apparatus in which it was originally drilled orcounterbored, or this may be done in any suitable appliance made for thepurpose or even by the light stroke of a hammer or by force appliedthrough a wrench or like tool in the hands of a skillful workman. Thepressure and strain being brought equally on opposite sides of the webor flange, there is practically no tendency, so long as the rollersproperly bear against one another, to throw the flange or web or theears thereof out of their proper plane and position, and should thishappen from any cause the natural tendency is by reason of the strain onopposite sides and on a common through pin or rivet to restore the partsto their true and proper positions.

It will be seen, particularly upon referring to Fig. 3, that by reasonof the employment of the sleeves which constitute in, fact, the axlesfor the rollers I am enabled to use relatively large and strong axles,while by employment of the rivets of smaller diameter passing throughthe sleeves or bushings I avoid unduly weakening the ears and I retain asufficient body of metal therein to resist the tendency of the metal totear out under the great strain brought upon the roller-teeth. In otherwords, while employing a relatively large and strong tubular axle foreach roller or roller-section the holes passing through the web orflange of the wheel or through the ears thereof are comparatively small.The tensile strength of the rivet being great and there being but littlelongitudinal strain brought thereon the use of small rivets ispermissible whenthe bushings are provided.

I am aware that it has been proposed to construct a sprocket-wheel inthe form of a disk or circular body having on its opposite facescircumferentially-grooved rollers connected by a through-pin passingthrough the Wheel or disk parallel with its axis, the grooved rollersbeing supported upon ball-bearings. Such a construction I do not claim,nor is it practicable for the purpose of intermeshing gear-wheels, forthe reason, among others, that the rim or periphery of the Wheel is notof such form as to permit two such wheels to act in conjunction.

It is important that the rollers be either truly cylindrical or trulyconical, or, in other words, that their outer faces form straight linesin the general direction of their axes, to the end that there may be acomplete line contact from end to end.

Having thus described my invention, what I claim is- 1. A gear-wheelconsisting of a disk or body, a series of stationary axles carried at ornear the periphery thereof, and rollers carried by said axles in pairs,one roller of each pair on one side of the disk or body and the otherroller on the other side thereof.

2. In a gear-wheel,the combination of a disk or body; a series of axlesprojecting from opposite faces thereof at or near its periphery;

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and straight-faced rollers applied to said axles on opposite sides ofthe disk or body.

3. In a gear-wheel, the combination of a body having its peripheryprovided with alternate ears or projections and recesses or depressionsadapted to receive corresponding ears or projections; and a series ofrollers carried in pairs by the ears or projections, the rollers of eachpair being on opposite sides of the carrying ear or projection.

4. The herein-described gear-wheel, coinprising a body A; a series ofprojections or ears b; a series of depressions c alternating andcorresponding in form with the ears b; axles supported by the ears b andprojecting on opposite sides thereof; and rollers B applied to saidaXles.

5, In a gear-wheel the combination of a body or disk provided withperipheral ears or projections b; rivets or fastenings D passing throughthe ears -b and projecting on opposite sides thereof; bushingsencircling said fastenin gs and secured thereby to the ears Z9; androllers encircling the bushings substantially as and for the purpose setforth.

6. In combination with disk or body A having counterbored ears or projections b; sleeves or bushings having their inner ends seated in thecounterbores of the ears; rollers encircling said sleeves; andfastenings passing through the sleeves and serving to retain saidsleeves and the rollers in position.

7. The combination substantially as herein set forth, of two coactinggear members, each provided with projecting ears and interveningrecesses, said ears being provided on both outer faces withrollers,substantiallyas shown and described.

S. A bevel-gear consisting of a body or disk A having a peripheraliiange at an angle to the plane of rotation, and provided with alternateprojections and depressions; and sectional conical rollers carried byand upon op posite sides of said projections and having their axes andtheir longitudinal surfaces radial to a common point or center in theaxial line of the wheel.

9. The combination of two bevel gearwheels each comprising a disk orbody having a peripheral fiange at an angle to said body, formed, withalternate projections and de-` pressions, each Wheel provided with aseries of rollers arranged in pairs, the rollers of the respective pairsbeing carried upon opposite sides or faces ofthe respective peripheralprojections, and having a common center from which their axes radiate,substantially as set forth.

10. In a gear-wheel, the combination of a main body or disk provided onopposite faces With short axles, each consisting of a tubular sleeve,each sleeve on one side being in alinement with another on the oppositeside; and

CHARLES L. TRAVIS.

Witnesses:

L. J. DAvIDs, CHAs. R. CHUTE.

